In the prior art, data transmission and reception between a rotating side and a fixed side has been performed. For example, a camera is provided on a rotatable base, and image signals or similar from the camera are transmitted to a fixed-side signal processing portion, and similar. In this case, image signals from the camera have been transmitted to the fixed-side signal processing portion by direct connection of wires between the camera and the signal processing portion. However, due to recent advances in wireless technology, it has become possible to transmit and receive signals (data) between a rotating side and a fixed side, even when there is no direct connection of wires.
However, in order to cause image capture or other operations on the rotating side, power must be supplied to the rotating side; but there has been the problem that the supply of power from a fixed side to a rotating side without contact is difficult.
In the past, when addressing these problems, for signal transmission, a plurality of light-emitting elements are provided on the upper portion of a disc-shape rotating body, and a plurality of light-receiving elements of a fixed body are provided at positions opposing the light-emitting elements, with data transmitted and received without contact, or for power transmission, with a rotating transformer configured between the rotating side and the fixed side, to realize a method of non-contact power supply from the fixed side to the rotating side (see for example Japanese Patent Application Laid-open No. 2002-75760, and Japanese Patent Application Laid-open No. 2006-197553).
However, in Japanese Patent Application Laid-open No. 2002-75760, when the speed of data communication increases, it is not always possible transmit all of the data from the light-emitting element of the rotating body to the light-receiving element of the fixed body. That is, in Japanese Patent Application Laid-open No. 2002-75760, the optical path from the light-emitting element is switched to another light-emitting element so that there is no interruption of the non-contact optical connection between optical elements accompanying rotation of the rotating body. When using this switching method, as the data communication speed increases, there are cases in which data is transmitted faster than the processing time to switch the optical path, and so the problem has occurred that the continuity of high-speed communication cannot be secured.
Also, in Japanese Patent Application Laid-open No. 2006-197553, because light-receiving element switching is no longer necessary, high-speed communication can be accommodated; but a mechanism (gears or similar) to control the rotation speed is needed, and backlash of the mechanism components must be considered. Moreover, light from a light-emitting element is dispersed before being received, so that only a portion of the light emitted reaches to the light-receiving element, and so the problem arises that application to analog signal communication is not possible.
The present invention was devised in light of the above problems, and has as an object the provision of a non-contact connector which enables multi-channel analog communication, without the need to consider backlash or similar, while securing continuity of high-speed communication.